purfying organic solid

Question 1

What is step 1?

Answer 1

= dissolve the impure compound in a minimum volume of hot solvent (near boiling)
REASON:
= an approprtiate solvent is one that will dissolve both compound and impurities when hot and one where the compound itself does not dissolve well when cold
= minimum volume: obtain a saturated solution
= enable crystalisation and cooling

Question 2

What is step 2?

Answer 2

= hot filter solution through filter paper quickly
= remove any insoluable impurities and heat will prevent crystals reforming during filtration

Question 3

What is step 3?

Answer 3

= cool the filtered solution by inserting beaker in ice
= crystals will reform but soluable impurities will remain in the solution, form because they are present in small quantities so solution is not saturated ice will increase thr yield of crystals

Question 4

What is step 4?

Answer 4

= suction filtrate with bunchner flask and funnel to seperate crystals
= the water pump connected to the bucnher flask reduces the pressure and speeds up filtration

Question 5

What is step 5?

Answer 5

= wash the crystals with distilled water removes soluable impurities

Question 6

What is step 6?

Answer 6

= dry the crystaks vetwen absorbent paper